Intracellular receptors (IRs) form a class of structurally-related genetic regulators scientists have named “ligand dependent transcription factors.” R.M. Evans, Science, 240:889 (1988). Steroid receptors are a recognized subset of the IRs, including the progesterone receptor (PR) androgen receptor (AR), estrogen receptor (ER), glucocorticoid receptor (GR) and mineralocorticoid receptor (MR). Regulation of a gene by such factors requires both the IR itself and a corresponding ligand, which has the ability to selectively bind to the IR in a way that affects gene transcription.
A compound that binds an IR and mimics the effect of the native ligand is referred to as an “agonist”, while a compound that inhibits the effect of the native ligand is called an “antagonist.” The term “modulators” refers to compounds that are agonists, partial agonists or antagonists.
The effectiveness of known modulators of steroid receptors is often tempered by their undesired side-effect profile, particularly during long-term administration. For example, the effectiveness of progesterone and estrogen agonists, such as norgestrel and diethylstilbesterol, respectively, as female birth control agents must be weighed against the increased risk of breast cancer and heart disease to women taking such agents. Similarly, the progesterone antagonist, mifepristone (RU486), if administered for chronic indications, such as uterine fibroids, endometriosis and certain hormone-dependent cancers, could lead to homeostatic imbalances in a patient due to its inherent cross-reactivity as a GR antagonist. Accordingly, identification of compounds that have good specificity for one or more steroid receptors, but have reduced or no cross-reactivity for other steroid or intracellular receptors, would be of significant value in the treatment of male and female hormone responsive diseases.
A group of quinolinone and coumarin analogs having a fused ring system of the aryl, piperidine, pyrrolidine, or indoline series have been described as androgen modulators. See U.S. Pat. No. 5,696,130; Int. Patent Appl. WO 97/49709; L.G. Hamann, et al. J. Med. Chem., 41:623–639 (1998); J. P. Edwards, et al., Bioorg. Med. Chem. Lett., 8:745–750 (1998); J. P. Edwards, et al, Bioorg. Med. Chem. Lett., 9:1003–1008 (1999), R. I. Higuchi, et al., Bioorg. Med. Chem. Lett., 9:1335–1340 (1999).
The entire disclosures of the publications and references referred to above and hereafter in this specification are incorporated herein by reference and are not admitted to be prior art.